President Park Geun-hye on Tuesday warned that North Korea’s development of submarine-launched ballistic missiles posed a “grave challenge” to regional peace, as the military stepped up efforts to boost its anti-submarine capabilities to better counter the threat.

She also called for “stern punishment” in case of any provocation in the skirmish-prone West Sea, following the communist neighbor’s repeated threats over the weekend to strike South Korean Navy vessels that it claimed were breaching its waters.

Cross-border tension is rising after Pyongyang last week succeeded in ejecting a dummy projectile from a newly developed 2,000-ton submarine off the eastern coastal city of Sinpo, a key early stage in developing SLBMs. It also fired three short-range ship-to-ship missiles into the East Sea. 

In light of the underwater test, the country is expected to be able to deploy ballistic missile-equipped submarines as early as two to three years from now, and fully achieve SLBM capability in four to five years, Seoul military officials said.

Park convened her first meeting with foreign and defense chiefs in about a year, calling for airtight military readiness and measures to better respond to the neighbor’s accelerating development of asymmetric weapons. It was the sixth edition since she assumed office in February 2013.

“North Korea’s ongoing development of SLBMs, which defies U.N. Security Council resolutions banning all launches using ballistic missile technology and related activities, poses a grave challenge to the stability not only on the Korean Peninsula but also in East Asia,” she was quoted as saying at the meeting by Cheong Wa Dae spokesman Min Kyung-wook.

Among the participants in the session were National Security Office chief Kim Kwan-jin, presidential Chief of Staff Lee Byung-kee, Foreign Minister Yun Byung-se, Defense Minister Han Min-koo, Unification Minister Hong Yong-pyo, National Intelligence Service director Lee Byung-ho, and Kim Kyou-hyun, head of the secretariat of the National Security Council.

With the mounting SLBM threats, South Korea will adjust and extend the concept of the Kill Chain preemptive strike system and Korea Air and Missile Defense program to be built by the early 2020s, the Defense Ministry said.

The military will also shore up its anti-submarine capabilities based on the principles of “detect, defense, disrupt and destroy” or “4D” ― the four major steps to respond to the North’s nuclear and missile attacks, a senior official noted. South Korea and the U.S. have been working to translate the concept into their wartime operational plans.

The “detect” represents the allies’ procedures to track North Korea’s missile movements with various intelligence-gathering assets, while the “defense” refers to a set of the allied defensive operations to minimize any damage from potential attacks.

The “disrupt” means striking North Korea’s core missile facilities including supporting installations, followed by the allies’ efforts to “destroy” its mobile transporter-erector-launchers and incoming missiles.

“We can expand the concept of the Kill Chain and KAMD given that it’s possible to attack multiple targets with the same apparatus,” ministry spokesman Kim Min-seok said at a news briefing.

“The expanded concept will help us prop up our operational plans and inject more funding if needed.”

The countermeasures reflect remarks by Defense Minister Han Min-koo at a parliamentary session Monday that the existing designs of the Kill Chain and KAMD systems have “limits” in responding to SLBM threats because their chief targets are ground-launched missiles.

Criticism also grew that Seoul had not adequately forecast Pyongyang’s SLBM advancement and devised steps to head it off, despite the allies’ years of monitoring. Its midterm defense plan for 2016-20 did not address the SLBM threats and projects on maritime patrol aircraft and long-distance acoustic sensors were put on the back burner.

In recent years, the North has carried out a string of onshore and undersea ejection tests as part of its efforts to secure the triad of delivery tools of a nuclear arsenal, which also include strategic bombers and intercontinental ballistic missiles.

Yet the latest experiment fueled concerns that it could help acquire a survivable second-strike capability, beef up the country’s nuclear deterrence and ultimately take its threat to a new level. Missile launches from submerged vessels are harder to detect than land-based ones.

“The underwater missile test shows that North Korea’s missile capabilities are advancing at a clip that is concerning, if not alarming,” Victor Cha, the Korea Chair at the Center for Strategic and International Studies in Washington, wrote on the think tank’s website on Monday.

“The North is moving headlong toward the development of a modern, survivable nuclear deterrent, with the full range of capacity from battlefield nuclear forces to high-yield fission and fusion weapons.”

Seoul and Washington are forecast to further review the progress on Pyongyang’s SLBM capability and discuss ways to intensify intelligence sharing including with Tokyo at an Asia security conference in Singapore later this month where Han and his U.S. and Japanese counterparts are slated to take part.

Adm. Choi Yun-hee, chairman of the Joint Chiefs of Staff, also held consultations and fine-tuned their responses on Tuesday with Gen. Curtis Scaparrotti, commander of U.S. Forces Korea, following their talks on Friday.

U.S. Secretary of State John Kerry, for his part, is scheduled to visit Seoul on May 17-18 as the allies are gearing up for a summit later this year in Washington between Park and U.S. President Barack Obama.

“We will look into various ways to respond (to the ejection test) at an international level based on discussions with the U.S. and other countries,” Foreign Ministry spokesperson Noh Kwang-il said at a press briefing, hinting at the possible engagement of the U.N.

By Shin Hyon-hee (heeshin@heraldcorp.com)